The problem : how can sticker stain in hardwood lumber be prevented?

Sticker stain results from the concentration of certain materials contained in the sap, probably forms of sugar, and oxidation of these materials. Microscopic examination of wood containing chemical stain discloses the presence of amber-colored particles in the parenchyma cells of the wood rays. If these particles remained widely dispersed, their oxidation would not result in the conspicuous dark sticker marks. Although chemical stain usually appears as sticker stain, it can also appear as dark streaks or patches on the lumber between the tiers of stickers. Complete information on the subject of sticker stain is not available, but the conditions under which it is likely to occur are known. Retarded air drying, either in the whole board or in sections of the board, encourages sticker stain. Temperature influences the formation of sticker stain, and lumber piled during the late fall and winter is less likely to stain than that piled during the other seasons of the year.